The molecular weight and molecular weight distribution of proteoglycans isolated from rat skin will be obtained by light scattering and viscometric techniques. The age dependent changes in these physical chemical proterties will be studied. The hydration properties of each proteoglycan fraction will be studied by high vacuum water vapor sorption techniques. Hydration studies will also be performed on combined fraction in order to elicit if cooperative effects contribute to the hydration properties. Rat cornea and aorta will be fractionated regarding their macromolecular components. Once the components are isolated the age dependent macromolecular distribution in each tissue will be studied.